Aerosol fire extinguisher and method

ABSTRACT

THERE IS PROVIDED AN IMPROVED FIRE EXTINGUISHING COMPOSITION FOR DISPENSING FROM AN AEROSOL-TYPE CONTAINER, WHICH COMPOSITION EXISTS UNDER SUPERATMOSPHERIC PRESSURE AND IS FORMED FROM A TETRAHALOGENATED METHANE CONTAINING AT LEAST ONE ATOM EACH OF CHLORINE, BROMINE, AND FLUORINE, A SECOND TETRAHALOGENATED METHANE IN WHICH THE HALOGEN SUBSTITUENTS ARE ONLY CHLORINE AND FLUORINE, AND HAVING DISSOLVED THEREIN AN INERT GAS.

April 16, 1974 J BECKER ET AL 3 804-5759 AEROSOL FIRE EXTINGUISHER AND METHOD Original Filed Dec. 27, 1971 20282 2 8 $66534 3 I I 0 T r 4 1|, 1 6 TI 2 (2/3 a 6 4 6 4 6 O 1 l 8 8 m 6 d 8 4 8 United States Patent O 3,804,759 AEROSOL FIRE EXTINGUISHER AND METHOD James R. Becker, 2984 Essex Road, Cleveland Heights, Ohio 44118, and Richard H. Furlow, 4701 Jefferson St., Midland, Mich. 48640 Original application Dec. 27, 1971, Ser. No. 212,439, now Patent No. 3,721,300, dated Mar. 20, 1973. Divided and this application Jan. 4, 1973, Ser. No. 320,945

Int. Cl. A62d 1/00 U.S. Cl. 2528 6 Claims ABSTRACT OF THE DISCLOSURE There is provided an improved fire extinguishing composition for dispensing from an aerosol-type container, which composition exists under superatmospheric pressure and is formed from a tetrahalogenated methane containing at least one atom each of chlorine, bromine, and fluorine, a second tetrahalogenated methane in which the halogen substituents are only chlorine and fluorine, and having dissolved therein an inert gas.

RELATED APPLICATIONS This application is a division of our copending application Ser. No. 212,439 filed Dec. 27,1971, now Pat. No. 3,721,300 dated Mar. 20, 1973 and is also related to our divisional application Ser. No. 320,944 filed Jan. 4, 1973 directed to the method of filling an aerosol fire extinguisher.

BACKGROUND OF THE INVENTION AND PRIOR ART The present invention relates to fire extinguishers of sufficiently small size and economy to permit transportation and use in automobiles or aircraft and for general household use. Heretofore, fire extinguishers have tended toward the inert gas type or combinations of such inert gases with Water. These structures have tended to be rather large and heavy for containing sufficient extinguishing material to handle the normal conflagration encountered under the conditions set forth above, and hence there has been a real need for a relatively small-sized economical, hand-operable fire extinguisher, using an inert gas as a propellant in solution in the extinguishing composition, but containable in a vessel having a yield pressure of 800 p.s.i. or less.

There have recently been developments in the field of flame-extinguishing compositions which are dependent upon halo-alkanes or mixtures thereof. Typical of these is the patent to Gambaretto 3,479,286 and the patent to Glew 3,106,530. The problems with these compositions have been that the containers heretofore available have normally been formed of materials which are sensitive to or unstable in the presence of the extinguishing composition, or suflicient propellant could not be introduced because of the limited strength of the container.

The present invention provides a fire extinguisher of sufliciently small size to be used in aircraft, automobiles, and homes, capable of containing under relatively low pressure a highly effective extinguishing compound containing dissolved therein an amount of inert gas sufficient to expel the composition and which composition has a vapor pressure of less than 110 p.s.i. at ordinary temperatures, but in excess of about 35 p.s.i. As the inert gas propellant, there may be used, in order of preference, carbon dioxide, nitrogen, helium, or argon.

It has also been discovered that a more effective fire extinguisher may be prepared by filling and refilling the bottles of the present invention by a process which involves blending two diiferent tetrahalogenated methanes to form a homogeneous mixture thereof, and subsequently 3,804,759 Patented Apr. 16, 1974 'ice introducing carbon dioxide under pressure, preferably with agitation; or, alternatively, adding the inert gas, e.g. CO to the tetrahaloalkanes first, for example, just prior to filling. The container with CO may be used to achieve the desired pressure. It has also been found convenient to premix the CO with both tetrahalogenated methanes and then add CO to pressurize the can to a predetermined desired pressure.

BRIEF DESCRIPTION OF THE INVENTION Briefly stated, therefore, the present invention is in the provision of a hand-operable fire extinguisher. This extinguisher is preferably formed of aluminum metal insofar as it is in prolonged contact with the fire extinglishing composition (except the nozzle portion). The preferred metallic components include an aluminum metal pressurewithstanding bottle which has an internally threaded neck at the open end. A metallic or plastic riser pipe extending from near the closed end of the bottle is provided along with an externally threaded metal coupler body which includes means for securing one end of the riser pipe and is adapted for threaded engagement with the internally threaded neck at the open end of the bottle. Metal refilling valve means are provided in the outer end of the coupler and comprise a telescopically movable hollow cylindrical valve body closed at its inner extremity and having radially disposed port means extending through the cylindrical sidewall adjacent the inner extremity. The cylindrical valve sleeve surrounds the valve body, and the valve body includes an externally accessible flanged portion. Spring means are provided coacting between the valve sleeve and the flanged portion to bias the valve body in the normally closed position. Removable nozzle means, preferably formed of plastic, are threadedly secured to the distal extremity of the coupler body and are provided with an internal shoulder adapted to engage and depress the flanged portion to open the refilling valve. The nozzle means include separate valve means and a spring-biased handle for opening and closing the nozzle valve in response to manual pressure. The fire extinguisher is completed by a liquid fire extinguishing composition contained within the bottle under pressure, which composition is stable in the presence of the preferred aluminum and consists essentially of a homogeneous mixture of from 1090 parts by weight of a tetrahalogenated methane containing at least one atom each of chlorine, bromine, and fluorine; from -10 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents are only fluorine and chlorine, the total of these halogenated methanes being parts by volume; and from 1-12 parts by weight of inert gas, preferably CO dissolved therein.

In filling and refilling the tire extinguishers of the present invention, best results have been secured when the fully halogenated methanes are blended together initially, and the inert gas then introduced into the homogeneous mixture with agitation and under pressure. It is desirable that the mixture be agitated during introduction of the inert gas. It has also been found that the inert gas may be dissolved in one tetrahalogenated methane at a point remote from the filling site and this solution blended with the other tetrahalogenated methane, preferably with agitation and under pressure just prior to filling.

BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawings there is shown a partially crosssectioned and partially cut away elevation of a fire extinguisher body in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now more particularly to the annexed drawings, there is here shown in partial cross-section and partially cut away fire extinguisher body including an aluminum bottle closed at its lower end by a cap 12 and provided with an internally threaded neck portion 14. Alternatively, an impact extrusion bottle having an integral end closure 12 may be used. An aluminum metal or plastic riser pipe 16 is centrally disposed within the aluminum bottle 10. The lower extremity 19 of the pipe 16 is disposed near, i.e. from about As" to A", the bottom 12.

An aluminum metal coupler body 18 is provided and threaded adjacent its lower extremity 20 for threaded engagement with the internal threads 22 of the neck 14. Coupler body 18 may be crimped into place within the neck 14. Suitable ring seal means 24 may be provided to aid in retention of fluid and pressure within the bottle 10. An internal bore 26 is provided for receipt and frictional retention of the proximal extremity 28 of pipe 16. Also, elastomeric ring sealing means 30 may be provided. The bore 26 and the extremity 28 may be threaded if desired.

The coupler body 18 includes intermediate threads 32 for receipt and retention of a nozzle body 34 hereafter more particularly described. The distal extremity of the coupler body 18 is provided with a cylindrical bore 36 into which is telescopically fitted a hollow cylindrical valve body 38 closed at its lower extremity 40 by any suitable means such as a Washer 42 over stud 44 threadedly retained within the cylindrical valve body 38 by a nut 46. Radial ports 50 and 52 allow for passage of fluid rising in riser pipe 16 through the sidewalls of the hollow cylindrical valve body 38. The upper extremity of the valve body 38 is provided with a flange 54. The upper extremity of the coupler body is provided with a recessed shoulder 56, and a coil spring 58 located in the resulting recess between the shoulder 56 and the flange 54 to urge the valve body 38 into a normally closed position. Suitable peripheral seals 60 and 62 prevent loss of fluid in the clearance between the coupler body 18 and the telescopically movable valve body 38 and between the outer periphery of the coupler body 18 and the nozzle member 34.

The nozzle member is conveniently formed of plastic such as urea formaldehyde or Bakelite and is desirably internally threaded as at 64 for threaded engagement with the threads 32 of coupler body 18. The nozzle means 34 is provided with a relatively deep recess 66 for receipt of the distal extremity of the coupler body 18, the recess 66 terminating in a shoulder 68 which coacts with the flange portion 54 of the valve body 38 to depress the latter against the bias of spring 58 and to expose the radial ports 50 and 52 to the hollow interior of the coupler body 18. The shoulder 68 surrounds a port 70 within the nozzle 34 which closed off by cyclindrical valve 72 which is slidable in cylindrical bore 74. Suitable seals 76 and 78 are provided to prevent escape of fluid. The valve 72 is provided with a seat portion 80 for seating coaction with valve seat 82 in nozzle body 34. A handle 84 is pivotally secured about pivot 86 and is provided with a projection 88 adapted for rolling coaction in slot 90 in the valve 72. T o bias the valve 72 in a normally closed position against valve seat 82, there is provided a recess 92 in the handle portion 84, a rounded headed pin 94 mounted in socket 96, and a biasing spring 98 coating between the bottom of the recess 92 and the head of the pin 94 to maintain the handle 84 in a fully extended position.

THE FIRE EXTINGUISHING COMPOSITION As indicated above, the fire extinguishing composition is composed of a blend of two tetrahalogenated methanes. The first of these is characterized by the presence of at least three different halogen atoms, namely chlorine, fluoline, and bromine. Thus, the first component of the fire extinguishing composition may be CF ClBr, CCl FBr, or CBr FCl, or a mixture thereof. The second component of the fire extinguishing composition is a methane derivative containing only chlorine and fluorine and is also tetrahalogenated. Thus, the second component may be CCl F CCl F, or CClF or a mixture thereof. The third principal ingredient of the fire extinguishing compositions of the present invention is an inert gas, such as carbon dioxide. It has been found from experience that the inert gas component is conveniently introduced after the two tetrahalomethanes have been thoroughly blended together. The propellant gas is then introduced under pressure and preferably with agitation; it is then uniformly dispersed and dissolved in the resulting composition and exhibits therein a vapor pressure at ordinary temperatures suificient to expel the extinguishing composition at ordinary temperatures but well below the yield pressure of an economic container. The vapor pressure of CO in the system is such that a sufiicient quantity can be dissolved to expel completely (until the bottom of the riser 16 is exposed) the contents of the bottle. The amount of gaseous CO which would otherwise be required in other extinguisher systems would exceed the yield point of an aluminum body of the economic dimensions useful with the present compositions.

The bromofluorochloromethane component is normally present in an amount ranging from 10-90 parts by weight and the chlorofluoromethane derivative normally present in a range of from -10 parts by weight, the summation of the tetrahalomethane components being 100 parts by weight. A convenient mixture of the tetrahalomethanes is a 50-50 mixture by volume, and it is preferred that the range be Within the limits of 30-70 to 70-30. The amount of inert gas by volume at standard conditions ranges from 1-12 parts. Normally from 8-10 parts by weight of carbon dioxide are incorporated, preferably in the manner aforesaid.

Filling and refilling of the fire extinguisher body is normally accomplished at room temperatures, for example 68 P. where the tetrahalomethanes are conveniently retained in the liquid state under pressure without substantial loss by vaporization. These materials are mutually soluble in all proportions and are conveniently blended under pressure initially. The inert gas is introduced under pressure, for example 15 atmospheres, through the neck of the bottle. If the bottle is agitated or shaken during the pressure introduction of inert gas, from 1-12 parts by weight of gas may be introduced into the composition. It has been found that when the carbon dioxide is introduced in this manner, substantially improved consistency in fire extinguisher properties are observed, e.g. extinguisher pressure, rate of discharge and fire extinguishing action.

Filling and refilling is done through the valve in the coupler body by filling apparatus which depresses the cylindrical valve body 38. As soon as the filling apparatus is removed, the spring 58 closes the valve by raising the valve body 38 so as to seal OK the radial ports 50 and 52. The fire extinguisher assembly is completed by threadably securing the preformed plastic handle and nozzle portion to the coupler body 18. Advancement of the nozzle 34 downwardly upon the coupler body 18 again depresses the cylindrical valve body 38 so that when the valve 72 is unseated, fluid retained within the bottle 10 under pressure may then be forced through the rise 16 into the hollow interior of the valve body 38 through the radial ports 50 and 52 into the opening 70 in nozzle body 34 and out the opening 100 in nozzle 34. At ordinary temperatures the pressure within the vessel is approximately 40 p.s.i. At a temperature of approximately F., the pressure is about 150 p.s.i. These limits allow snflicient expulsion of the contents which are highly eflicient fire extinguishing materials under a variety of temperatures such as may be encountered in use in an airplane or an automobile or a household without imposing any hazard at elevated temperatures normally encountered.

There has thus been provided an improved fire extinguisher formed from aluminum and containing a highly efficient extinguishing composition which is substantially nonreactive with the container materials. These extinguishers are of small size, easily carried, and hand-operated and utilize an extinguishing material of high efficiency.

What is claimed is:

1. A fire extinguishing composition existing under super atmospheric pressure comprising:

(a) from -90 parts by weight of a tetrahalogcnated methane containing at least one atom each of chlorine, bromine, and fluorine;

(b) from 90-10 parts by weight of tetrahalogenated methane in which the halogen substituents are only chlorine and fluorine atoms, the total of (a) and (b) being 100 parts by weight;

(c) from 1 to 12 parts by weight of an inert gas selected from the group consisting of carbon dioxide, nitrogen, helium, and argon dissolved in components (a) and (b).

2. A fire extinguishing composition in accordance with claim 1 wherein the inert gas is carbon dioxide.

3. A fire extinguishing composition in accordance with claim 1 wherein component (a) is selected from the group consisting of CF ClBr, CCl FBr, CBr FCl, and mixtures thereof.

4. A fire extinguishing composition in accordance with claim 1 wherein component (b) is selected from the group consisting of CCI F CCl F, CClF and mixtures thereof.

5. A composition in accordance with claim 1 wherein component (a) is selected from the group consisting of CF ClBr, CCI FBr, CBr FCl, and mixtures thereof; component (b) is selected from the group consisting of CCl F CCI F, CClF and mixtures thereof; and com ponent (c) is carbon dioxide.

6. A fire extinguishing composition existing under super atmospheric pressure comprising:

(a) from -70 parts by Weight of a tetrahalogenated methane containing at least one atom each of chlorine, bromine and fluorine;

(b) from 30 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents are only fluorine and chlorine, the total of components (a) and (b) being parts by Weight; and

(c) from 8-10 parts by weight of an inert gas selected from the group consisting of carbon dioxide, nitrogen, helium, and argon dissolved in components (a) and (b).

References Cited UNITED STATES PATENTS 2,653,130 9/1953 Eiseman 252--8 2,837,891 *6/ 1958 Stasiak 2528 FOREIGN PATENTS 1,236,064 6/ 1971 Great Britain 252-8 LELAND A. SEBASTIAN, Primary Examiner 

